Referencing Namespaces

Lets say you have a process control system that monitors and reacts to monitored systems that supply status information in XML form.

Those instance documents each conform to a schema, but each monitored system has a different schema.

The database performs various actions based on those instance documents.

Those instance documents are initially staged in a single table (acting as a holding pen), with the XML just being one column in the table along with a few other scalar datatype columns.

Lets say you want to index that table.  Pre 11gR2, I would use a function based index using EXTRACTVALUE on an XML element, creating as many indexes as needed to cover the major queries performed on the table.  Now this method is being deprecated and we are supposed to use XMLIndex.